Each tower heater contains bulbs that illuminate when the sauna is powered on. If one or both bulbs aren’t lighting up, here’s how to troubleshoot and diagnose the problem.

Please take photos or videos at each step of the troubleshooting process. If we need to order replacement parts, our Support team will use these to process your warranty claim.

⚠ Important: Unplug the sauna from the wall before checking any wiring connections.

Step 1: Diagnose the Problem

The steps below depend on whether one bulb is out or both are out at the same time.

One Bulb Out

A single bulb that won’t light is almost certainly a failed bulb. Contact Plunge Support to order replacements, and be sure to mention your sauna model — bulbs vary between models.

Both Bulbs Out

If both bulbs are out simultaneously, a loose connection is more likely the cause than two bulbs failing at once. Check the following before ordering replacements:

• Back cavity connections: Ensure all wiring connections in the back cavity of the sauna are firmly seated.
• Roof connections: Using a ladder, check all roof connections — particularly the C13/C14 connectors on the control box power bay.
• Under the tower heater: Remove the bolts holding the tower heater to the glass panel and check the C13/C14 connection underneath the heater. Press it firmly to confirm it’s fully seated, then reinstall the heater and test.

If all connections are solid and the bulbs still won’t light, you likely have a failed bulb or bulbs. Contact Plunge Support to order replacements, and be sure to mention your sauna model — bulbs vary between models.